ארבע גישות לספר תהלים: מר' סעדיה גאון עד ר' אברהם אבן עזרא : כולל שריד משיטה ראשונה של פירוש ראב"ע לתהלים שעדיין לא ראתה אור

A comprehensive description of a fascinating chapter in the history of Jewish biblical interpretation - a multi-faceted controversy regarding the nature of the psalms and their prophetic status.
Rabbi Saadia Gaon saw the book of Psalms as a kind of second Torah, which is all prophecy, and there is no prayer in it. Whereas the Karaite commentators Yaphet ben Ali and Salmon ben Yeruham saw in it the arrangement of Israel's obligatory prayers.
In stark contrast to all his predecessors, the great Sephardi commentator only Rabbi Moshe Ibn Jakatila treated the psalms as non-prophetic supplications and praises; Whereas Rabbi Avraham Ibn-Ezra returned to a position quite close to that of the sages - the psalms as prophetic sacred poetry.